Method of preparing graphene with lignin solution

The invention discloses a method of preparing graphene with lignin solution, which includes the steps of dissolving lignin in an alkaline solution, wherein the lignin, which is extracted from papermaking black liquid, is employed as a reduction agent and a stabilizing agent, and performing a redox reaction to the lignin solution with a graphene oxide water solution under a heating condition to prepare stably-dispersed graphene by means of control on reaction temperature, reaction time and lignin concentration. The method is simple in operations, is a green, environment-friendly and quick graphene preparing method and completely satisfies the demand of green chemistry. Lignin is a natural biomass resource which is abundant, but however, is discharged as wastes largely, so that the method not only discloses a new approach of green-synthesis of graphene, but also has an important significance of development of high-valued utilization on resources.